Practice vs. carry ammo

This is a discussion on Practice vs. carry ammo within the Defensive Ammunition & Ballistics forums, part of the Defensive Carry Discussions category; Hello all. First post here. I have been lurking for a bit and just registered. Hopefully some of you knowledgable folks here can enlighten me ...

Practice vs. carry ammo

Hello all. First post here. I have been lurking for a bit and just registered. Hopefully some of you knowledgable folks here can enlighten me as I have not really found good explanations anywhere on the web. I am new to hand guns and will soon be looking to purchase a sig p229 of some variety...probably an elite stainless. in researching what ammo to use I keep coming across posts saying such things as 'i carry xammo but practice with anything i can get my hands on thats cheap.'
My question is this: if you are going to carry a specific ammo how does practicing with anything else (unless, perhaps, it is of the same weight and velocity) help you to really improve. imagine a situation in which one is practicing all day long with gold dot .40 180g which tend to have a POI at a specific place when you are sighting. then you walk around carrying 165g. wouldnt these shoot differently? recoil (impact on ability to control double taps), trajectory, etc...
obvioulsy it would be pretty expensive to practice only on your carry ammo but can someone detail for me the thinking process here as it seems counterintuitive.
thanks in advance. I already have learned much reading here and hope to get even more.

If the majority of your practice is in the most likely range that you will encounter in an actual incident, 10yds & in there will be little difference. In addition, a majority of it will be unsighted fire.

As Guantes mentioned, most ammo will not be very far off (assuming they are relatively close in weight) at normal practice distances. If you are shooting 50 yard bullseye, then sure, it will matter. If you are putting rapid fire into the centerline of a human sized target at 10m and in, it's unlikely that you'll even notice the difference.

My duty round is 124gr Hydra-Shok, and my practice round is 124gr NATO ball. There is no noticeable difference until you get out around 25m, and even then it's minor. Keep your duty and practice loads "close," and it won't be an issue.

All that said, the fundamentals remain the same no matter the type/weight of ammo. If you focus on those during every practice session, YOU will get better, and that is much more important than any fraction of a gram difference in bullet weight.

A man fires a rifle for many years, and he goes to war. And afterward he turns the rifle in at the armory, and he believes he's finished with the rifle. But no matter what else he might do with his hands - love a woman, build a house, change his son's diaper - his hands remember the rifle.

Welcome to the forum!
Not everyone can afford to practice with premium defensive ammo. This very issue was addressed by Winchester and Bass Pro Shops. BPS is the exclusive retail outlet for Winchester's SXZ ammo. You can get SXZ defense ammo which is hollow point or the SXZ practice ammo which is ballistically identical FMJ with a bullet that has the same profile as the JHP. The practice ammo is a few dollars a box cheaper but gives the same trajectory, recoil, and muzzle blast as the JHP. Basically if you mixed them up in a magazine you could not tell the difference shot to shot.

Thanks...this seems to confirm what i was thinking. i was just confused as to why people were practicing with such different rounds...like a 155 for practice because it was cheap and then the 180 for carry.
if you want to use speer gold dot .40 180g for your carry ammo can someone please suggest a good practice round which would be cheaper? I certainly couldnt afford to practice as much as I hope to with the good stuff!

As the guys said before if you get a FMJ .40 round and your practice is 10-15 yards there will be very little change in point of impact and very little difference though some in your recoil. Use the same companies FMJ ammo for practice as you do their defensive ammo for carry and light practice if you like.

Practicing with range ammo helps you with drawing, sighting, defensive moves, and general gun handling. It keeps you in the habit of hearing a BANG when you pull the trigger. It gives you the basics, just like ice skaters doing figures or boxers at the punching bag. Using your SD ammo reminds you of the POA, noise, and flash of that particular round.

I'll practice 50 rounds a week with range ammo and a full mag (13 or 10 - depending) with SD ammo.

great points. Guess I had mainly been thinking about what happened AFTER the gun was raised and sighted. But all of the aspects prior to that are just as important. from what i am finding on the web it looks like a company like Speer makes the same ammo but in FMJ which runs on average about 40-50% less. I like your practice ammo regimen idea Keltyke. getting in a mag of the SD ammo to every 2 or 3 of SD.
Thanks!